Prostate cancer is the most commonly diagnosed non-cutaneous neoplasm among males in the US, resulting in an estimated 27,360 deaths in the year 2009. The advent of widespread PSA (prostate specific antigen) screening has resulted in increased detection of prostate cancer and detection at earlier stages of carcinogenesis. This clear success is tempered by the fact that some of these cancers may be of limited clinical significance, that men with histologically similar disease often exhibit widely varying outcomes following local therapy (i.e. prostatectomy or radiation) and that metastasis is strongly associated with cancer-specific mortality. Clearly, improved methods for stratification of patients into risk groups independent of or in combination with existing clinical parameters are needed for appropriate patient management. We discovered a suite of DNA based biomarkers that appear to predict recurrence and metastasis at the time of primary treatment based on copy number within the tumor genome. These biomarkers (called GEMCaP (Genomic Evaluators of Metastatic Prostate Cancer)) may be well suited for a clinical prognostic assay to stratify prostate cancer patients as to risk of postoperative recurrence and thus assist with treatment decisions after initial therapy. The focus of this proposal is to take the next steps toward translation of the GEMCaP risk assessment assay into the clinic. Thus, the central goals of this project are to validate our results of predicting recurrence with external samples and a high resolution GEMCaP assay, demonstrate the feasibility and reproducibility of an external laboratory performing the assay and evaluate GEMCaP as an independent predictor of progression free survival when added to a validated clinical post-operative nomogram.